U.S. patent application number 12/067087 was filed with the patent office on 2009-11-19 for air conditioning apparatus.
This patent application is currently assigned to DAIKIN INDUSTRIES, LTD.. Invention is credited to Makoto Kojima, Takayuki Setoguchi.
Application Number | 20090282861 12/067087 |
Document ID | / |
Family ID | 37888790 |
Filed Date | 2009-11-19 |
United States Patent
Application |
20090282861 |
Kind Code |
A1 |
Setoguchi; Takayuki ; et
al. |
November 19, 2009 |
AIR CONDITIONING APPARATUS
Abstract
A supercooling heat exchanger of an air conditioning apparatus
is configured to exchange heat between a high-pressure refrigerant
and a low-pressure refrigerant. The supercooling heat exchanger is
divided into first and second heat exchangers. One of the first and
second heat exchangers is disposed so that the high-pressure
refrigerant and the low-pressure refrigerant flow countercurrent to
each other. The other of the first and second heat exchangers is
disposed so that the high-pressure refrigerant and the low-pressure
refrigerant flow parallel to each other. Preferably, both heat
exchangers have a high-pressure liquid refrigerant pipe that is
wound around the external periphery of a low-pressure refrigerant
suction pipe. The heat exchangers are thereby reduced in size.
Inventors: |
Setoguchi; Takayuki; (
Osaka, JP) ; Kojima; Makoto; (Osaka, JP) |
Correspondence
Address: |
GLOBAL IP COUNSELORS, LLP
1233 20TH STREET, NW, SUITE 700
WASHINGTON
DC
20036-2680
US
|
Assignee: |
DAIKIN INDUSTRIES, LTD.
Osaka-shi, Osaka
JP
|
Family ID: |
37888790 |
Appl. No.: |
12/067087 |
Filed: |
September 15, 2006 |
PCT Filed: |
September 15, 2006 |
PCT NO: |
PCT/JP2006/318376 |
371 Date: |
March 17, 2008 |
Current U.S.
Class: |
62/525 |
Current CPC
Class: |
F25B 13/00 20130101;
F25B 40/00 20130101; F28D 7/0016 20130101; F25B 2313/02741
20130101; F28D 7/106 20130101 |
Class at
Publication: |
62/525 |
International
Class: |
F25B 39/02 20060101
F25B039/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 22, 2005 |
JP |
2005-275493 |
Claims
1. An air conditioning apparatus comprising: a supercooling heat
exchanger configured to exchange heat between a low-pressure
refrigerant and a high-pressure refrigerant, the supercooling heat
exchanger being divided into first and second heat exchangers; one
of the first and second heat exchangers being arranged such that
the high-pressure refrigerant and the low-pressure refrigerant flow
countercurrent to each other; and the other of the first and second
heat exchangers being arranged such that the high-pressure
refrigerant and the low-pressure refrigerant flow parallel to each
other.
2. The air conditioning apparatus according to claim 1, wherein
each of the first and second heat exchangers has a high-pressure
liquid refrigerant pipe wound around an external periphery of a
low-pressure refrigerant suction pipe.
3. The air conditioning apparatus according to claim 1, wherein
each of the first and second heat exchangers a high-pressure liquid
refrigerant pipe fitted around an external periphery of a
low-pressure refrigerant suction pipe in a coaxial manner, the
high-pressure liquid refrigerant pipe being larger in diameter than
the low-pressure refrigerant suction pipe.
Description
TECHNICAL FIELD
[0001] The present invention relates to an air conditioning
apparatus that uses a supercooling heat exchanger.
BACKGROUND ART
[0002] FIG. 4 shows a configuration of an air conditioning
apparatus that uses a conventional supercooling heat exchanger.
[0003] In this air conditioning apparatus, a compressor 1, a
four-way switching valve 2, an outdoor-side heat exchanger 3 that
functions as a condenser during the cooling operation and as an
evaporator during the heating operation, a heating expansion valve
4, a receiver 5, a cooling expansion valve 6, an indoor-side heat
exchanger 8 that functions as an evaporator during the cooling
operation and as a condenser during the heating operation, and
other components are connected sequentially via the four-way
switching valve 2, thereby constituting a refrigerating cycle for
air conditioning as is shown in the drawing.
[0004] The switching operation of the four-way switching valve 2
allows a refrigerant to be reversibly circulated in the direction
shown by solid arrows in the drawing during the cooling operation,
and in the direction shown by dashed arrows in the drawing during
the heating operation, thereby resulting in cooling and heating,
respectively.
[0005] The outdoor-side heat exchanger 3 and the indoor-side heat
exchanger 8 are both configured to include numerous refrigerant
paths. Therefore, even if the capacity of the flow divider portion
to distribute the refrigerant is improved to a maximum, it is
difficult to distribute the refrigerant evenly throughout the
refrigerant paths.
[0006] In view of this, when the outdoor-side heat exchanger 3 or
the indoor-side heat exchanger 8 functions as the evaporator, the
amount of pressure reduction in the heating expansion valve 4 or
cooling expansion valve 6 is appropriately set so that the
refrigerant of the exit side of the outdoor-side heat exchanger 3
or the indoor-side heat exchanger 8 is in appropriately humidified
condition. Thus, maximum performance as the evaporator can be
guaranteed even if, for example, the refrigerant drifts into the
outdoor-side heat exchanger 3 or the indoor-side heat exchanger 8,
and therefore the evaporator can be made as compact as
possible.
[0007] The performance of the evaporator can be further improved by
removing the refrigerant supercooling of the exit side of the
condenser, increasing the difference in enthalpy of the evaporator
side to reduce circulating volume, and reducing the pressure loss
on the evaporator side. This is accomplished by providing a
liquid-gas heat exchanger 13 having a double pipe structure,
composed of a low-pressure refrigerant suction pipe 14 as an inner
pipe and a high-pressure liquid refrigerant pipe 15 as an outer
pipe, as a supercooling heat exchanger.
[0008] In this liquid-gas heat exchanger 13, e.g., the flow rate of
the refrigerant, the length of the double pipes, the inside
diameter of the outer pipe, and the outside diameter of the inner
pipe are set in a predetermined manner appropriately.
[0009] As the liquid-gas heat exchanger 13 is provided in this
manner, the refrigerant of the exit side of the evaporator is
superheated, backflow into the compressor 1 can be prevented, the
refrigerant of the exit side of the condenser is supercooled, and
the difference in enthalpy of the evaporator side can be increased
to reduce circulating volume. Therefore, the pressure loss can also
be reduced, and the evaporator 8 (or the evaporator 3) can be made
even more compact (see Patent Document 1 as an example).
[0010] [Patent Document 1]
[0011] Japanese Laid-open Patent Publication No. 5-332641
(Specification pg. 1-5, FIGS. 1-5)
DISCLOSURE OF THE INVENTION
<Problems the Invention is Intended to Solve>
[0012] However, a supercooling heat exchanger in which heat is
exchanged between a high-pressure refrigerant and a low-pressure
refrigerant as described above has problems in that since the
refrigerant flows in opposite directions during cooling and
heating, the flows are parallel in either of the operating modes,
and heat exchange is less efficient. For example, in the case shown
in FIG. 4, the flows are countercurrent to each other during
cooling and are parallel to each other during heating, causing heat
exchange to be less efficient.
[0013] The present invention was designed in order to resolve such
problems, and an object thereof is to provide an air conditioning
apparatus comprising a supercooling heat exchanger for exchanging
heat between a low-pressure refrigerant and a high-pressure
refrigerant, wherein the supercooling heat exchanger is divided
into a first heat exchanger and a second heat exchanger, either one
of these heat exchangers is disposed so that the high-pressure
refrigerant and the low-pressure refrigerant flow countercurrent to
each other, and the other heat exchanger is disposed so that the
high-pressure refrigerant and the low-pressure refrigerant flow
parallel to each other, whereby the above-described problems with
conventional practice are appropriately resolved.
<Means for Solving These Problems>
[0014] To achieve these objects, the present invention is
configured with the following means of solving these problems.
[0015] (1) Invention of a First Aspect
[0016] The means for solving the problems in accordance with this
aspect is an air conditioning apparatus comprising a supercooling
heat exchanger 13 for exchanging heat between a low-pressure
refrigerant and a high-pressure refrigerant, characterized in that:
the supercooling heat exchanger 13 is divided into two first and
second heat exchangers 13A, 13B; either the first heat exchanger
13A or the second heat exchanger 13B is disposed so that the
high-pressure refrigerant and the low-pressure refrigerant flow
countercurrent to each other; and the other heat exchanger, i.e.,
either the second heat exchanger 13B or the first heat exchanger
13A, is disposed so that the high-pressure refrigerant and the
low-pressure refrigerant flow parallel to each other.
[0017] The supercooling heat exchanger 13 for exchanging heat
between a high-pressure refrigerant and a low-pressure refrigerant
as previously described has problems in that since the refrigerants
flow in opposite directions during cooling and heating, the flows
are parallel in either of the operating modes, and heat exchange is
less efficient.
[0018] However, as described above, the supercooling heat exchanger
13 is divided into two heat exchangers, i.e., the first heat
exchanger 13A and the second heat exchanger 13B, either the first
heat exchanger 13A or the second heat exchanger 13B is disposed so
that the high-pressure refrigerant and the low-pressure refrigerant
flow countercurrent to each other, and the other heat exchanger,
i.e., either the second heat exchanger 13B or the first heat
exchanger 13A is disposed so that the high-pressure refrigerant and
the low-pressure refrigerant flow parallel to each other, whereby
the supercooling heat exchanger 13 can maintain its heat exchange
performance without variation even if the direction of refrigerant
flow changes during cooling or heating.
[0019] (2) Invention of a Second Aspect
[0020] The means for solving the problems in accordance with this
aspect is characterized in that, in the configuration of the means
for solving the problems in accordance with the invention of the
first aspect, the first and second heat exchangers 13A, 13B are
both configured by winding a high-pressure liquid refrigerant pipe
15 around the external periphery of a low-pressure refrigerant
suction pipe 14.
[0021] Thus, when the first and second heat exchangers 13A, 13B are
both configured by winding the high-pressure liquid refrigerant
pipe 15 around the low-pressure refrigerant suction pipe 14, the
capacity of the heat exchanger itself does not need to be
increased, and the supercooling heat exchangers 13A, 13B can be
made as small as possible.
[0022] (3) Invention of a Third Aspect
[0023] The means for solving the problems in accordance with this
aspect is characterized in that, in the configuration of the means
for solving the problems in accordance with the invention of the
first aspect, the first and second heat exchangers 13A, 13B are
both configured by fitting a high-pressure liquid refrigerant pipe
15 around the external periphery of a low-pressure refrigerant
suction pipe 14 in a coaxial structure, wherein the high-pressure
liquid refrigerant pipe 15 is larger in diameter than the
low-pressure refrigerant suction pipe 14.
[0024] Thus, when the first and second supercooling heat exchangers
13A, 13B both have a double-pipe structure in which the
high-pressure liquid refrigerant pipe 15 is fitted coaxially over
the low-pressure refrigerant suction pipe 14, the structures of the
supercooling heat exchangers 13A, 13B themselves are
simplified.
EFFECT OF THE INVENTION
[0025] According to the present invention, as a result of the
above, the supercooling heat exchanger can maintain high heat
exchange performance even when the flows of the refrigerants change
direction during cooling and heating. As a result, the evaporator
can be made more compact.
[0026] In this case, when the each heat exchanger is configured by
winding a high-pressure liquid refrigerant pipe around a
low-pressure refrigerant suction pipe, the supercooling heat
exchanger itself can be made as small as possible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a refrigeration circuit diagram showing the
configuration of an air conditioning apparatus according to
Preferred Embodiment of the present invention;
[0028] FIG. 2 is an enlarged view showing the portion of the first
and second liquid-gas heat exchangers as relevant parts of the same
apparatus;
[0029] FIG. 3 is an enlarged view showing a portion of the first
and second liquid-gas heat exchangers according to another
embodiment of the present invention; and
[0030] FIG. 4 is a refrigerant circuit diagram showing the
configuration of a conventional example of air conditioning
apparatus.
DESCRIPTION OF THE REFERENCE SYMBOLS
[0031] 1 Compressor [0032] 2 Four-way switching valve [0033] 3
Outdoor-side heat exchanger [0034] 4, 6 Expansion valves [0035] 5
Receiver [0036] 8 Indoor-side heat exchanger [0037] 13A First heat
exchanger [0038] 13B Second heat exchanger [0039] 14 Low-pressure
refrigerant suction pipe [0040] 15 High-pressure liquid refrigerant
pipe [0041] 16 Muffler
BEST MODE FOR CARRYING OUT THE INVENTION
[0042] FIGS. 1 and 2 of the attached drawings show the
configuration of the entirety and relevant parts of the refrigerant
circuits in an air conditioning apparatus according to a preferred
embodiment of the present invention.
[0043] First, as shown in FIG. 1, in the air conditioning apparatus
of this embodiment, a compressor 1, a four-way switching valve 2,
an outdoor-side heat exchanger 3 that functions as a condenser
during the cooling operation and as an evaporator during the
heating operation, a heating expansion valve 4, a receiver 5, a
cooling expansion valve 6, an indoor-side heat exchanger 8 that
functions as an evaporator during the cooling operation and as a
condenser during the heating operation, and other components are
connected sequentially via the four-way switching valve 2, thereby
constituting a refrigerating cycle for air conditioning as shown in
the drawing.
[0044] The switching operation of the four-way switching valve 2
allows refrigerant to be reversibly circulated in the direction
shown by solid arrows in the diagram during the cooling operation,
and in the direction shown by dashed arrows in the diagram during
the heating operation, thereby resulting in cooling and heating,
respectively.
[0045] A liquid-gas heat exchanger 13 is provided in this
embodiment as well as the case in FIG. 4 described previously. This
liquid-gas heat exchanger 13 comprises a low-pressure refrigerant
suction pipe 14 and a high-pressure liquid refrigerant pipe 15, and
is used as a supercooling heat exchanger for exchanging heat
between low-pressure refrigerant and high-pressure refrigerant.
[0046] As the liquid-gas heat exchanger 13 is provided in this
manner, refrigerant of the exit side of the evaporator is
superheated, backflow into the compressor 1 can be prevented, the
refrigerant of the exit side of the condenser is supercooled, and
the difference in enthalpy of the evaporator side can be increased
to reduce refrigerant circulating volume, as was described
previously. Therefore, pressure loss can also be reduced, and the
evaporator (the indoor-side heat exchanger 8 during cooling or the
outdoor-side heat exchanger 3 during heating) can be made as
compact as possible.
[0047] However, in this embodiment, unlike in the case in FIG. 4
described previously, the liquid-gas heat exchanger 13 is divided
into two liquid-gas heat exchangers, i.e., a first liquid-gas heat
exchanger 13A and a second liquid-gas heat exchanger 13B in which
refrigerants flow in mutually opposite directions. The first heat
exchanger 13A may, for example, be disposed so that the
high-pressure refrigerant and low-pressure refrigerant flow
countercurrent to each other, and the second heat exchanger 13B may
be disposed so that the high-pressure refrigerant and low-pressure
refrigerant flow parallel to each other.
[0048] Therefore, with this configuration, the liquid-gas heat
exchanger 13 can maintain its performance without variation as
shown in the diagrams, even when the refrigerant flow changes
direction during cooling and heating. As a result, the refrigerant
of the exit side of the condenser is supercooled without variation
during heating, and the difference in enthalpy of the evaporator
side can be increased to reduce the circulating volume.
[0049] Moreover, the first and second liquid-gas heat exchangers
13A, 13B are both configured so that the high-pressure liquid
refrigerant pipe 15 from the exit side of the condenser that is
smaller in diameter than the low-pressure refrigerant suction pipe
14 is wound in a helical structure in mutually opposite directions,
for example, as shown in detail in FIG. 2, around the external
periphery of the low-pressure refrigerant suction pipe 14. The
existing low-pressure refrigerant suction pipe 14 leads from the
indoor-side heat exchanger (evaporator) 8 during cooling or from
the outdoor-side heat exchanger (evaporator) 3 during heating back
to the refrigerant suction inlet in the compressor 1 via the
four-way switching valve 2. Therefore, the supercooling heat
exchanger 13 itself can have a small capacity and can be made as
small in size as possible.
[0050] The improvement in supercooling heat exchange efficiency is
effective in contributing to making the evaporators themselves
smaller and more compact.
[0051] Furthermore, winding the high-pressure liquid refrigerant
pipe 15 around the existing low-pressure refrigerant suction pipe
14 as shown in FIG. 2 makes it possible to inhibit increases in
suctioned gas pressure loss, and to prevent the COP from
decreasing.
[0052] The reference numeral 16 in FIG. 2 denotes a muffler for gas
refrigerant in the low-pressure refrigerant suction pipe 14.
OTHER EMBODIMENTS
[0053] In the above embodiment, the divided first and second heat
exchangers 13A, 13B have a structure in which a high-pressure
liquid refrigerant pipe 15 having a small diameter is helically
wound around an existing low-pressure refrigerant suction pipe 14
that goes from the four-way switching valve 2 to the refrigerant
suction inlet of the compressor 1, as shown in FIG. 2. In another
possible configuration, as shown in FIG. 3, for example, the first
and second heat exchangers 13A, 13B have a double-pipe structure in
which a high-pressure liquid refrigerant pipe 15 larger in diameter
than the low-pressure refrigerant suction pipe 14 is fitted as a
coaxial structure around the external periphery of the low-pressure
refrigerant suction pipe 14, and these pipes are disposed so that
the refrigerant flows in mutually opposite directions.
[0054] Thus, as the first and second heat exchangers 13A, 13B for
supercooling have a double-pipe structure in which the
high-pressure liquid refrigerant pipe 15 is fitted as a coaxial
structure around the low-pressure refrigerant suction pipe 14, the
structure of the supercooling heat exchanger itself is
simplified.
INDUSTRIAL APPLICABILITY
[0055] The present invention can be widely utilized within the
field of air conditioning apparatuses that use supercooling heat
exchangers.
* * * * *